Can anyone tell me the maximum number of campaings allowed per adwords account. I know it used to be 20.
StupidScript is correct that the maximum number of campaigns is in fact 25. This number may be able to be increased in special cases, by contacting AdWords support and briefly explaining why more campaigns are needed.
I think it's 2000 keywords per ad group.
At one time, there was a suggested limit of 2000 keywords per campaign. At present, the actual number of keywords that may be used in an account can vary, and depends (among other things) on how successfully keywords have been used in the account, historically.
AWA